As a newfound Nader lover, this is definitely extremely annoying. Let alone I have stopped counting the times I’ve been practically teamkilled by a magician walking through me when I was cooking a nade as Fragger…
I was thinking out of curiosity how team collision would help this situation actually, instead of FF. I know it wouldn’t solve the issue of “hey where the hell did that guy come from” situations when sonic-speed Proxy flies around a corner just to catch and absolutely blob your epicly calculated direct hit nade soaring through the air approaching the medic you were targeting. But on the other hand it would cease teammates magically appearing behind you, moving through you and resulting in explosive load right at your feet unloading a frag full of nopes on your beloved pelvic volvo.
You could basically still be annoyed by occasional teammates appearing from thin air from your sides. But it would leave you some more room to actually take into account teammates surrounding you while preparing to throw or launch the projectile.
On the other hand some doorways are really tight and I think team collision has been left out of the game precisely for its chaotic (in pubs only though) and fast paced nature. Ain’t none got time fo’ dat Rhino to politely relocate his enourmous gluteus maximuses into another dimension outta doorway in Underground when you have some C4 to defuse.